<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>定位</title>
  <style>
    .box {
      position: absolute;
      background-color: antiquewhite;
      left: 100px;
      top: 200px;
    }
    .hey {
      position: relative;
      background-color: azure;
      left: 10px;
      top: 30px;
    }
    .father {
      position: relative;
      border: 1px solid #000;
      height: 300px;
    }
    .son {
      position: absolute;
      left: 200px;
      top: 50px;
      background-color: bisque;
    }
  </style>
</head>
<body>
  <div class="box">
    hello
  </div>
  <!-- <div class="hey">
    world
  </div> -->
  <div>!!!</div>

  <div class="father">
    <div class="son">son</div>
  </div>
</body>
</html>